The present invention relates to a vehicle lamp device in the form of a high-mount stop lamp or the like mounted on an upper surface of a rear end portion or on a roof of a vehicle body for warning following vehicles.
A high-mount stop lamp is a lamp device employed for the purpose of warning following vehicles upon braking so as to enhance road safety. Such a high-mount stop lamp is designed to be brightly lit together with a brake light during braking so as to make drivers of following vehicles pay greater attention to thereby prevent a rear-end collision or the like from occurring.
Recently, such a high-mount stop lamp has been incorporated in a spoiler 2 disposed on upper surface of a rear end portion of a vehicle body 1 as shown in FIGS. 1 and 2. As shown in those figures, reference numeral 3 designates a high-mount stop lamp constituted by a lamp unit 6 having a lamp body 4 and a front face lens 5, a printed substrate 7 fixed to an attachment portion 4A of the lamp body 4 by a bolt V, and a large number of light-emitting diodes (LEDs) 8 disposed on a surface of the printed substrate 7 arranged parallel to one another at predetermined intervals in the transverse direction of the vehicle body 1. The lamp 3 is incorporated in the spoiler 2 with the front face lens 5 covering an opening portion 9 formed in a rear end surface of the spoiler 2. Reference numeral 12 designates a cylindrically shaped lead-wire lead-out portion integrally formed on a back surface of the lamp body 4, and reference numeral 13 designates an insertion hole formed in a partition wall 14 dividing the inside of the spoiler 2 into two (front and rear) chambers 17A and 17B. Rubber bushings 15 and 16 are fitted in the wire lead-out portion 12 and the insertion hole 13 respectively. Lead wires 10 of the high-mount stop lamp 3 are inserted into the lamp unit 6 through wire insertion holes formed in the rubber bushings 15 and 16 and are connected to an electric circuit on the printed substrate 7.
In such a high-mount stop lamp 3 in which LEDs 8 are generally used as light sources, however, there has been a problem in that, since the lamp body 4 and front face lens 5 are arranged to constitute a completely enclosed type lamp unit 6, when moisture in the air sealed inside the lamp unit 6 in the assembly of the lamp condenses on the inner surface of the front face lens 5 in the form of water droplets as the ambient temperature drops, the quantity of light from the LEDs 8 transmitted through the front face lens 5 is decreased to thereby reduce the lighting efficiency.
Japanese Laid-Open Patent Publications Nos. 61-160328, 61-160329, 61-160330, and 61-160331 teach various lighting arrangements in spoilers. None of these, however, disclose a solution to the moisture accumulation problem.
Co-asigned U.S. Pat. Nos. 4,733,335 and 4,744,011 disclose vehicle lamps provided with air passageways to relieve moisture buildup. However, the structures of those lamps are not suitable for a spoiler-mounted lamp unit.